feat(sdk): re-export Protocol/ProtocolSpec from shared/protocol; add server/zod-compat subpath

Author: felixweinberger

packages/sdk/package.json

@@ -52,6 +52,14 @@
             "types": "./dist/server/mcp.d.ts",
             "import": "./dist/server/mcp.mjs"
         },
+        "./server/zod-compat.js": {
+            "types": "./dist/server/zod-compat.d.ts",
+            "import": "./dist/server/zod-compat.mjs"
+        },
+        "./server/zod-compat": {
+            "types": "./dist/server/zod-compat.d.ts",
+            "import": "./dist/server/zod-compat.mjs"
+        },
         "./server/stdio.js": {
             "types": "./dist/server/stdio.d.ts",
             "import": "./dist/server/stdio.mjs"

packages/sdk/src/server/zod-compat.ts

@@ -0,0 +1,16 @@
+// v1 compat: `@modelcontextprotocol/sdk/server/zod-compat.js`
+// v1 unified Zod v3 + v4 types. v2 is Zod v4-only, so these collapse to the
+// v4 types. Prefer `StandardSchemaV1` / `StandardSchemaWithJSON` for new code.
+
+import type * as z from 'zod';
+
+/** @deprecated Use `StandardSchemaV1` (any Standard Schema) or a Zod type directly in v2. */
+export type AnySchema = z.core.$ZodType;
+
+/** @deprecated Use `Record<string, z.ZodType>` directly in v2. */
+export type ZodRawShapeCompat = Record<string, AnySchema>;
+
+/** @deprecated */
+export type AnyObjectSchema = z.core.$ZodObject | AnySchema;
+
+export type { StandardSchemaV1, StandardSchemaWithJSON } from '@modelcontextprotocol/server';

packages/sdk/src/shared/protocol.ts

@@ -1,16 +1,15 @@
 // v1 compat: `@modelcontextprotocol/sdk/shared/protocol.js`
-// Protocol class is no longer public in v2; subclass Client or Server instead.
-// Re-exporting the option types and context types that v1 callers commonly
-// imported from this path.
 
 export type {
     BaseContext,
     ClientContext,
     NotificationOptions,
     ProtocolOptions,
+    ProtocolSpec,
     RequestOptions,
     ServerContext
 } from '@modelcontextprotocol/server';
+export { DEFAULT_REQUEST_TIMEOUT_MSEC, Protocol } from '@modelcontextprotocol/server';
 
 /** @deprecated Use {@link ServerContext} (server handlers) or {@link ClientContext} (client handlers) in v2. */
 // eslint-disable-next-line @typescript-eslint/no-unused-vars

packages/sdk/tsdown.config.ts

@@ -10,6 +10,7 @@ export default defineConfig({
         'src/experimental/tasks.ts',
         'src/server/index.ts',
         'src/server/mcp.ts',
+        'src/server/zod-compat.ts',
         'src/server/completable.ts',
         'src/server/sse.ts',
         'src/server/stdio.ts',